JP7049781B2 - Conductive members, electrochemical reaction units, and electrochemical reaction cell stacks - Google Patents

Description

The techniques disclosed herein relate to conductive members.

A solid oxide fuel cell (hereinafter referred to as "SOFC") is known as one of the fuel cells that generate power by utilizing an electrochemical reaction between hydrogen and oxygen. The fuel cell power generation unit (hereinafter referred to as “power generation unit”), which is a constituent unit of the SOFC, includes a fuel cell single cell (hereinafter referred to as “single cell”) and a conductive current collecting member. The single cell includes an electrolyte layer and an air electrode and a fuel electrode that face each other in a predetermined direction across the electrolyte layer. The current collector member is electrically connected to an air electrode or a fuel electrode constituting a single cell.

As a current collector member constituting a power generation unit, a current collector member manufactured by performing a hole drilling process or a bending process on a single metal plate is known (see, for example, Patent Document 1). In this current collector, the portion composed of the portion other than the bent portion of the metal plate (hereinafter referred to as "first conductive portion") has a predetermined direction (hereinafter referred to as "first direction"). It is a substantially flat plate-shaped part orthogonal to). Through holes are formed in the first conductive portion. Further, the second conductive portion formed of the bent portion of the metal plate is first conductive from the inner circumference of the first conductive portion forming the through hole in the first directional view. It is a portion including a plate-shaped portion extending in a direction intersecting the surface of the sex portion.

Japanese Unexamined Patent Publication No. 2013-55042

In the above-mentioned conventional current collector member, for example, during the operation of SOFC, the stress generated by the repeated thermal expansion and contraction of the current collector member is generated in a specific part of the current collector member (for example, in the current collector member). , At the end of the through hole in the second direction orthogonal to the boundary line between the first conductive portion and the second conductive portion (however, in the direction opposite to the tip end side of the second conductive portion). Of the facing parts, the parts that constitute the bent part (that is, the hole end facing portion, which will be described later, and the hole end facing portion is a part of the current collecting member) are concentrated as a result. There is a problem that cracks may occur at specific points in the current collector member.

It should be noted that such a problem is a collection of electrolytic cell units, which are constituent units of solid oxide-type electrolytic cells (hereinafter, also referred to as “SOEC”) that generate hydrogen by utilizing the electrolysis reaction of water. This is a common issue for electrical components. In this specification, the fuel cell power generation unit and the electrolytic cell unit are collectively referred to as an electrochemical reaction unit. Further, such a problem is not limited to SOFC and SOEC, but is a problem common to other types of electrochemical reaction units. Further, such a problem is not limited to the current collector member manufactured by drilling or bending a single metal plate, but is also a common problem for current collector members manufactured by other methods. Is. Further, such a problem is not limited to the current collecting member constituting the electrochemical reaction unit, but is a substantially flat plate shape containing metal and orthogonal to the first direction, and the first conductivity having a through hole formed therein. A first including a portion and a plate-like portion containing a metal and extending in a direction intersecting the surface of the first conductive portion from the inner circumference of the first conductive portion forming the through hole in the first direction view. It is a common problem in general for a conductive member including the conductive portion of 2.

This specification discloses a technique capable of solving the above-mentioned problems.

The techniques disclosed herein can be realized, for example, in the following forms.

(1) The conductive member disclosed in the present specification contains a metal, has a substantially flat plate shape orthogonal to the first direction, and includes a first conductive portion having a through hole formed and a metal. A second conductivity including a plate-shaped portion extending in a direction intersecting the surface of the first conductive portion from the inner circumference of the first conductive portion forming the through hole in the first direction view. In a conductive member comprising a portion, the through hole is in a second direction orthogonal to a boundary line between the first conductive portion and the second conductive portion in the first directional view. In the first hole portion facing the entire virtual line segment connecting between the two intersections of the straight line passing through the boundary line and the inner circumference of the first conductive portion, and in the second direction. Located on the side opposite to the first hole portion with respect to the virtual line segment, and on one side of the boundary line in the third direction parallel to the virtual line segment, in the first hole portion. The other of the continuous second hole portion and the boundary line in the second direction, located on the opposite side of the virtual line segment from the first hole portion and in the third direction. On the side, it has a third hole portion continuous with the first hole portion. In this conductive member, through holes formed in the first conductive portion are formed into the first hole portion, the second hole portion, and the third hole portion as described above by the above-mentioned virtual line segment. It is a structure that can be divided. Therefore, in the present conductive member, the hole end facing portion in the conductive member does not coincide with the position of the boundary line between the first conductive portion and the second conductive portion. That is, the hole end facing portion in the conductive member intersects a surface substantially parallel to the first conductive portion, such as the position of the boundary line between the first conductive portion and the second conductive portion. It is not continuous with the plate-shaped portion stretched in the direction (for example, is not bent), and has a substantially flat plate shape substantially parallel to the first conductive portion. Here, the hole end facing portion in the conductive member has a second direction orthogonal to the boundary line between the first conductive portion and the second conductive portion (however, the tip end side of the second conductive portion). Of the parts facing the end of the through hole in the opposite direction), it is a part that constitutes a bent part. Therefore, according to the present conductive member, when the conductive member repeats thermal expansion and contraction, for example, during operation of SOFC, stress is applied to a specific portion (for example, a portion facing the hole end) of the conductive member. Can be suppressed from concentrating. Therefore, according to the present conductive member, it is possible to suppress the occurrence of cracks at a specific portion of the conductive member.

(2) In the conductive member, the width of the first conductive portion and the width of the second conductive portion on the virtual line segment may be equal to each other. In this conductive member, there is no step at the position of the boundary line between the first conductive portion and the second conductive portion. Therefore, according to the present conductive member, it is possible to effectively suppress the concentration of stress in a specific portion of the conductive member (for example, a portion facing the hole end), and in a specific portion of the conductive member. It is possible to effectively suppress the occurrence of cracks.

(3) In the conductive member, each of the first conductive portion and the second conductive portion is formed on a plate-shaped metal member containing Cr and the surface of the metal member, and the said. It may be configured to have a coating layer that suppresses the diffusion of Cr from the metal member. According to the present conductive member, it is possible to suppress the occurrence of cracks in the coating layer at a specific portion of the metal member (for example, a portion constituting the hole end facing portion). Therefore, according to the present conductive member, the diffusion of Cr from the metal member can be effectively suppressed by the coating layer.

(4) The conductive member may be configured to satisfy the following formula (1).
2 × ta <ΔWa / 2 <Wam / 2 ・ ・ ・ (1)
however,
Wam: Of the metal member constituting the second conductive portion at a first position separated by a distance L1 along the surface of the second conductive portion in a direction orthogonal to the boundary line from the boundary line. Width (hereinafter referred to as "width Wam at the position of distance L1")
ΔWa: Difference (Wao-Wam) obtained by subtracting the width (width at the position of the distance L1) Wam from the opening width Wao of the metal member at a position separated by the distance L1 from the boundary line in the second direction.
ta: Thickness of the coating layer at the first position According to the present conductive member, the width (width at the position of the distance L1) Wam of the metal member constituting the second conductive portion is relatively large. Moreover, even if a coating layer is formed on the surface of the metal member, it is possible to suppress the occurrence of interference between the members (sites). Therefore, according to the present conductive member, the current collecting function of the conductive member deteriorates as the width (width at the position of the distance L1) Wam of the metal member constituting the second conductive portion becomes smaller. It is possible to suppress the occurrence of peeling of the coating layer and damage to the members due to interference between the members (parts) while avoiding the above.

(5) The conductive member may be configured to satisfy the following formulas (2) and (3).
ΔWb / 2 <Wbm / 2 ... (2)
Σtb <D ... (3)
however,
Wbm: In a virtual state in which the second conductive portion is rotated so as to have a posture substantially parallel to the first conductive portion with reference to the boundary line, the second direction from the boundary line. The width of the metal member constituting the second conductive portion at the second position separated by the distance L2 (hereinafter, referred to as "width Wbm at the position of the distance L2").
ΔWb: Difference (Wbo-Wbm) obtained by subtracting the width (width at the position of the distance L2) Wbm from the opening width Wbo of the metal member constituting the first hole portion in the second position in the virtual state. )
D: In the virtual state, the first conductivity forming the through hole from a point on the outer periphery of the metal member constituting the second conductive portion in the third direction at the second position. Shortest distance to the inner circumference of the portion Σtb: The sum of the thickness of the coating layer at the positions at both ends of the shortest distance According to this conductive member, the second conductivity is obtained when the metal member is manufactured by bending. The width (width at the position of the distance L2) Wbm of the metal member constituting the portion 232 can be made relatively large, and the coating layer can be uniformly formed on the surface of the metal member. Therefore, according to the present conductive member, the current collecting function of the conductive member is lowered as the width (width at the position of the distance L2) Wbm of the metal member constituting the second conductive portion 232 becomes smaller. While avoiding this, the coating layer can effectively suppress the diffusion of Cr from the metal member.

(6) In the conductive member, the coating layer may be configured to contain at least one of a spinel-type oxide and a perovskite-type oxide. According to the present conductive member, the diffusion of Cr from the metal member can be effectively suppressed by the coating layer.

(7) In the conductive member, among the corner portions forming the second hole portion, the corner portion closest to the third hole portion in the third direction and the third hole portion are formed. At least one of the corner portions closest to the second hole portion in the third direction may be R-shaped. Among the corners forming the second hole portion, the corner portion closest to the third hole portion in the third direction, and the corner portion forming the third hole portion, the third in the third direction. The corner portion closest to the hole portion of 2 is the hole end facing portion in the conductive member. In this conductive member, since the portion facing the hole end of the conductive member has an R shape, it is possible to extremely effectively suppress the concentration of stress and extremely effectively suppress the occurrence of cracks. can do.

(8) In the conductive member, the conductive member may be configured to be a solid oxide type electrochemical reaction unit. According to this conductive member, it is possible to suppress the occurrence of cracks at a specific portion of the conductive member for a solid oxide type electrochemical reaction unit.

(9) The electrochemical reaction unit disclosed in the present specification is an electrochemical reaction unit including an electrolyte layer containing a solid oxide and an air electrode and a fuel electrode facing each other in the first direction across the electrolyte layer. The cell and the conductive member arranged on one side of the first direction with respect to the electrochemical reaction single cell and functioning as a current collecting member electrically connected to the air electrode or the fuel electrode. To prepare for. According to the present electrochemical reaction unit, it is possible to suppress the occurrence of cracks at a specific portion of the conductive member that functions as a current collector member.

(10) In the electrochemical reaction unit, the electrochemical reaction unit may be configured to be a fuel cell power generation unit. According to the present electrochemical reaction unit, it is possible to suppress the occurrence of cracks at a specific portion of the conductive member that functions as a current collecting member for the fuel cell power generation unit.

(11) In the electrochemical reaction cell stack disclosed in the present specification, in the electrochemical reaction cell stack including a plurality of electrochemical reaction units arranged side by side in the first direction, the plurality of electrochemical reaction units are used. At least one is the electrochemical reaction unit. According to the present electrochemical reaction cell stack, it is possible to suppress the occurrence of cracks at specific points of the conductive member included in at least one electrochemical reaction unit constituting the electrochemical reaction cell stack.

The technique disclosed in the present specification can be realized in various forms, for example, a conductive member, a conductive member and an electrochemical reaction single cell (fuel cell single cell or electrolytic single cell). It is realized in the form of an electrochemical reaction unit (fuel cell power generation unit or electrolytic cell unit), an electrochemical reaction cell stack (fuel cell stack or electrolytic cell stack) having a plurality of electrochemical reaction units, a method for manufacturing them, and the like. It is possible.

It is a perspective view which shows the appearance structure of the fuel cell stack 100 in this embodiment. It is explanatory drawing which shows the XZ cross-sectional structure of the fuel cell stack 100 at the position of II-II of FIG. It is explanatory drawing which shows the YZ cross-sectional structure of the fuel cell stack 100 at the position of III-III of FIG. It is explanatory drawing which shows the XZ cross section composition of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. It is explanatory drawing which shows the YZ cross section configuration of two power generation units 102 adjacent to each other at the same position as the cross section shown in FIG. It is explanatory drawing which shows the XY cross-sectional structure of the power generation unit 102 at the position of VI-VI of FIG. 4 and FIG. It is explanatory drawing which shows the XY cross-sectional structure of the power generation unit 102 at the position of VII-VII of FIG. 4 and FIG. It is a flowchart which shows an example of the manufacturing method of the air electrode side current collector member 200. It is explanatory drawing which shows an example of the manufacturing method of the air electrode side current collector member 200. It is explanatory drawing which shows an example of the manufacturing method of the air electrode side current collector member 200. It is explanatory drawing which shows an example of the manufacturing method of the air electrode side current collector member 200. It is explanatory drawing which shows the detailed structure of the air electrode side current collector member 200 in this embodiment. It is explanatory drawing which shows the detailed structure of the air electrode side current collector member 200 in this embodiment. It is explanatory drawing which shows the virtual state which rotated the 2nd conductive part 232 of the air electrode side current collector member 200 so that it may have the posture substantially parallel to the 1st conductive part 231 with respect to the boundary line BL. It is explanatory drawing which shows the structure of the air electrode side current collector member 200X in the comparative example. It is explanatory drawing which shows the detailed structure of the fuel pole side current collector member 300 in this embodiment. It is explanatory drawing which shows the detailed structure of the air electrode side current collector member 200 in the modification. It is explanatory drawing which shows the detailed structure of the air electrode side current collector member 200 in the modification. Explanatory drawing which shows the virtual state which rotated the 2nd conductive part 232 of the air electrode side current collector member 200 in the modification so that it may have the posture substantially parallel to the 1st conductive part 231 with respect to the boundary line BL. Is.

A. Embodiment:
A-1. Constitution:
(Structure of fuel cell stack 100)
FIG. 1 is a perspective view showing an external configuration of the fuel cell stack 100 in the present embodiment, and FIG. 2 is an XZ of the fuel cell stack 100 at the position II-II in FIG. 1 (and FIGS. 6 and 7 described later). It is explanatory drawing which shows the cross-sectional structure, and FIG. 3 is an explanatory view which shows the YZ cross-sectional structure of the fuel cell stack 100 at the position of III-III of FIG. 1 (and FIGS. 6 and 7 which will be described later). Each figure shows XYZ axes that are orthogonal to each other to identify the direction. In the present specification, for convenience, the Z-axis positive direction is referred to as an upward direction, and the Z-axis negative direction is referred to as a downward direction, but the fuel cell stack 100 is actually in a direction different from such an orientation. It may be installed. The same applies to FIGS. 4 and later.

The fuel cell stack 100 includes a plurality of (seven in this embodiment) fuel cell power generation unit (hereinafter, simply referred to as “power generation unit”) 102, and a pair of end plates 104 and 106. The seven power generation units 102 are arranged side by side in a predetermined arrangement direction (vertical direction in this embodiment). The pair of end plates 104 and 106 are arranged so as to sandwich an aggregate composed of seven power generation units 102 from above and below. The arrangement direction (vertical direction) corresponds to the first direction in the claims.

A plurality of holes (eight in this embodiment) penetrating in the vertical direction are formed on the peripheral edge of each layer (power generation unit 102, end plates 104, 106) constituting the fuel cell stack 100 around the Z direction. , The holes formed in each layer and corresponding to each other communicate with each other in the vertical direction to form a communication hole 108 extending in the vertical direction from one end plate 104 to the other end plate 106. In the following description, the holes formed in each layer of the fuel cell stack 100 to form the communication holes 108 may also be referred to as communication holes 108.

A bolt 22 extending in the vertical direction is inserted into each communication hole 108, and the fuel cell stack 100 is fastened by the bolt 22 and the nuts 24 fitted on both sides of the bolt 22. As shown in FIGS. 2 and 3, between the nut 24 fitted on one side (upper side) of the bolt 22 and the upper surface of the end plate 104 constituting the upper end of the fuel cell stack 100, and the bolt. An insulating sheet 26 is interposed between the nut 24 fitted on the other side (lower side) of the 22 and the lower surface of the end plate 106 constituting the lower end of the fuel cell stack 100. However, in the place where the gas passage member 27 described later is provided, the insulating sheets arranged on the upper side and the lower side of the gas passage member 27 and the gas passage member 27 between the nut 24 and the surface of the end plate 106, respectively. 26 is intervening. The insulating sheet 26 is made of, for example, a mica sheet, a ceramic fiber sheet, a ceramic dust sheet, a glass sheet, a glass-ceramic composite agent, or the like.

The outer diameter of the shaft portion of each bolt 22 is smaller than the inner diameter of each communication hole 108. Therefore, a space is secured between the outer peripheral surface of the shaft portion of each bolt 22 and the inner peripheral surface of each communication hole 108. As shown in FIGS. 1 and 2, the position is near the midpoint of one side (the side on the positive side of the X axis among the two sides parallel to the Y axis) on the outer circumference of the fuel cell stack 100 around the Z direction. In the space formed by the bolt 22 (bolt 22A) and the communication hole 108 through which the bolt 22A is inserted, the oxidant gas OG is introduced from the outside of the fuel cell stack 100, and the oxidant gas OG is generated for each power generation. It functions as an oxidizer gas introduction manifold 161 that is a gas flow path supplied to the unit 102, and is the midpoint of the side opposite to the side (the side on the negative side of the X axis among the two sides parallel to the Y axis). The space formed by the bolt 22 (bolt 22B) located in the vicinity and the communication hole 108 through which the bolt 22B is inserted provides the oxidant off-gas OOG, which is the gas discharged from the air chamber 166 of each power generation unit 102. It functions as an oxidizer gas discharge manifold 162 that discharges to the outside of the fuel cell stack 100. In this embodiment, for example, air is used as the oxidant gas OG.

Further, as shown in FIGS. 1 and 3, the vicinity of the midpoint of one side (the side on the positive side of the Y axis among the two sides parallel to the X axis) on the outer circumference of the fuel cell stack 100 around the Z direction. In the space formed by the bolt 22 (bolt 22D) located at the center and the communication hole 108 through which the bolt 22D is inserted, the fuel gas FG is introduced from the outside of the fuel cell stack 100, and the fuel gas FG is generated for each power generation. A bolt 22 that functions as a fuel gas introduction manifold 171 to be supplied to the unit 102 and is located near the midpoint of the opposite side (the side on the negative side of the Y axis among the two sides parallel to the X axis). The space formed by (bolt 22E) and the communication hole 108 through which the bolt 22E is inserted causes the fuel off-gas FOG, which is the gas discharged from the fuel chamber 176 of each power generation unit 102, to the outside of the fuel cell stack 100. It functions as a fuel gas discharge manifold 172 to be discharged. In this embodiment, as the fuel gas FG, for example, a hydrogen-rich gas obtained by reforming a city gas is used.

The fuel cell stack 100 is provided with four gas passage members 27. Each gas passage member 27 has a hollow cylindrical main body portion 28 and a hollow cylindrical branch portion 29 branched from the side surface of the main body portion 28. The hole of the branch portion 29 communicates with the hole of the main body portion 28. A gas pipe (not shown) is connected to the branch portion 29 of each gas passage member 27. Further, as shown in FIG. 2, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22A forming the oxidant gas introduction manifold 161 communicates with the oxidant gas introduction manifold 161. The hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22B forming the oxidant gas discharge manifold 162 communicates with the oxidant gas discharge manifold 162. Further, as shown in FIG. 3, the hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22D forming the fuel gas introduction manifold 171 communicates with the fuel gas introduction manifold 171 and fuel gas. The hole of the main body 28 of the gas passage member 27 arranged at the position of the bolt 22E forming the discharge manifold 172 communicates with the fuel gas discharge manifold 172.

(Structure of end plates 104 and 106)
The pair of end plates 104 and 106 are substantially rectangular flat plate-shaped conductive members, and are made of, for example, stainless steel. One end plate 104 is located above the power generation unit 102 located at the top, and the other end plate 106 is located below the power generation unit 102 located at the bottom. A plurality of power generation units 102 are sandwiched by a pair of end plates 104 and 106 in a pressed state. The upper end plate 104 functions as a positive output terminal of the fuel cell stack 100, and the lower end plate 106 functions as a negative output terminal of the fuel cell stack 100.

(Structure of power generation unit 102)
FIG. 4 is an explanatory diagram showing an XZ cross-sectional configuration of a plurality of power generation units 102 at the same position as the cross section shown in FIG. 2, and FIG. 5 is an explanatory view of the plurality of power generation units 102 at the same position as the cross section shown in FIG. It is explanatory drawing which shows the cross-sectional structure of YZ. In the upper part of FIG. 5, the YZ cross-sectional structure of a part of the power generation unit 102 is enlarged and shown. Further, FIG. 6 is an explanatory diagram showing an XY cross-sectional configuration of the power generation unit 102 at the position of VI-VI of FIGS. 4 and 5, and FIG. 7 is a power generation unit at the position of VII-VII of FIGS. 4 and 5. It is explanatory drawing which shows the XY cross-sectional structure of 102.

As shown in FIGS. 4 and 5, the power generation unit 102 includes a single cell 110, a separator 120, an air pole side frame 130, an air pole side current collector 200, a fuel pole side frame 140, and a fuel pole side. It includes a current collector member 300 and a pair of interconnectors 150 that form the uppermost layer and the lowermost layer of the power generation unit 102. A hole corresponding to the communication hole 108 through which the bolt 22 described above is inserted is formed in the peripheral portion of the separator 120, the air pole side frame 130, the fuel pole side frame 140, and the interconnector 150 in the Z direction.

The interconnector 150 is a substantially rectangular flat plate-shaped conductive member, and is made of, for example, ferritic stainless steel. The interconnector 150 ensures electrical conduction between the power generation units 102 and prevents mixing of the reaction gas between the power generation units 102. In this embodiment, when two power generation units 102 are arranged adjacent to each other, one interconnector 150 is shared by two adjacent power generation units 102. That is, the upper interconnector 150 in one power generation unit 102 is the same member as the lower interconnector 150 in another power generation unit 102 adjacent to the upper side of the power generation unit 102. Further, since the fuel cell stack 100 includes a pair of end plates 104 and 106, the power generation unit 102 located at the top of the fuel cell stack 100 does not have the upper interconnector 150 and is located at the bottom. The power generation unit 102 does not include the lower interconnector 150 (see FIGS. 2 and 3).

Further, as shown in the partially enlarged view of FIG. 5, in the present embodiment, the surface of the interconnector 150 on the side facing the air electrode 114 is covered with the conductive coating layer 152. The coating layer 152 includes, for example, spinel-type oxides (for example, Mn _1.5 Co _1.5 O ₄ and Mn Co ₂ O ₄ , ZnCo ₂ O ₄ , ZnMn ₂ O ₄ , ZnMnCoO ₄ , CuMn ₂ O ₄ and the like) and the like. It is configured to contain a perovskite-type oxide (for example, a composite oxide containing La or Sr). In the following description, unless otherwise specified, the interconnector 150 means "interconnector 150 covered with a coating layer 152".

The single cell 110 has an electrolyte layer 112, a fuel electrode (anode) 116 arranged on one side (lower side) of the electrolyte layer 112 in the vertical direction (first direction), and the other side in the vertical direction of the electrolyte layer 112. It is provided with an air electrode (cathode) 114 arranged on the (upper side). The single cell 110 of the present embodiment is a fuel pole support type single cell that supports other layers (electrolyte layer 112, air pole 114) constituting the single cell 110 with the fuel pole 116.

The electrolyte layer 112 is a flat plate-shaped member having a substantially rectangular shape in the Z direction, and is a dense layer. The electrolyte layer 112 is formed of, for example, a solid oxide such as YSZ (yttria-stabilized zirconia), ScSZ (scandia-stabilized zirconia), SDC (samarium-doped ceria), GDC (gadolinium-doped ceria), and perovskite-type oxide. There is. That is, the single cell 110 (power generation unit 102) of the present embodiment is a solid oxide fuel cell (SOFC) that uses a solid oxide as an electrolyte.

The air electrode 114 is a substantially rectangular flat plate-shaped member smaller than the electrolyte layer 112 in the Z direction, and is a porous layer. The air electrode 114 is formed of, for example, a perovskite-type oxide (for example, LSCF (lanternstrontium cobalt iron oxide), LSM (lanternstrontium manganese oxide), LNF (lantern nickel iron)).

The fuel electrode 116 is a substantially rectangular flat plate-shaped member having substantially the same size as the electrolyte layer 112 in the Z direction, and is a porous layer. The fuel electrode 116 is formed of, for example, a cermet composed of Ni and oxide ion conductive ceramic particles (for example, YSZ).

The separator 120 is a frame-shaped member in which a substantially rectangular hole 121 penetrating in the vertical direction is formed near the center, and is formed of, for example, metal. The peripheral portion of the hole 121 in the separator 120 faces the peripheral edge of the surface of the electrolyte layer 112 on the side of the air electrode 114. The separator 120 is bonded to the electrolyte layer 112 (single cell 110) by a bonding portion 124 formed of a brazing material (for example, Ag wax) arranged at the facing portions thereof. The separator 120 partitions the air chamber 166 facing the air electrode 114 and the fuel chamber 176 facing the fuel electrode 116, and a gas leak from one electrode side to the other electrode side at the peripheral edge of the single cell 110. It is suppressed.

As shown in FIGS. 4 to 6, the air electrode side frame 130 is a frame-shaped member in which a substantially rectangular hole 131 penetrating in the vertical direction is formed near the center, and is formed of, for example, an insulator such as mica. ing. The hole 131 of the air pole side frame 130 constitutes an air chamber 166 facing the air pole 114. The air electrode side frame 130 is in contact with the peripheral edge of the surface of the separator 120 opposite to the side facing the electrolyte layer 112 and the peripheral edge of the surface of the interconnector 150 facing the air electrode 114. .. Further, the air electrode side frame 130 electrically insulates between the pair of interconnectors 150 included in the power generation unit 102. Further, in the air electrode side frame 130, the oxidant gas supply communication hole 132 that communicates the oxidant gas introduction manifold 161 and the air chamber 166, and the oxidant gas that communicates the air chamber 166 and the oxidant gas discharge manifold 162. A discharge communication hole 133 is formed.

As shown in FIGS. 4, 5 and 7, the fuel pole side frame 140 is a frame-shaped member in which a substantially rectangular hole 141 penetrating in the vertical direction is formed near the center, and is formed of, for example, metal. .. The hole 141 of the fuel electrode side frame 140 constitutes a fuel chamber 176 facing the fuel electrode 116. The fuel electrode side frame 140 is in contact with the peripheral edge of the surface of the separator 120 facing the electrolyte layer 112 and the peripheral edge of the surface of the interconnector 150 facing the fuel electrode 116. Further, in the fuel electrode side frame 140, a fuel gas supply communication hole 142 that communicates the fuel gas introduction manifold 171 and the fuel chamber 176, and a fuel gas discharge communication hole 143 that communicates the fuel chamber 176 and the fuel gas discharge manifold 172. And are formed.

As shown in FIGS. 4, 5 and 7, the fuel electrode side current collector member 300 is arranged in the fuel chamber 176. The fuel electrode side current collector member 300 is formed of, for example, a conductive material such as nickel or a nickel alloy. The fuel pole side current collector member 300 is in contact with the surface of the fuel pole 116 on the side opposite to the side facing the electrolyte layer 112, and is in contact with the surface of the interconnector 150 on the side facing the fuel pole 116. However, as described above, since the power generation unit 102 located at the bottom of the fuel cell stack 100 does not have the lower interconnector 150, the fuel electrode side current collecting member 300 in the power generation unit 102 has the interconnector 150. Is in contact with the lower end plate 106 instead of. Since the fuel electrode side current collector member 300 has such a configuration, the fuel electrode 116 and the interconnector 150 (or the end plate 106) are electrically connected to each other. The configuration of the fuel electrode side current collector member 300 will be described in detail later. The fuel electrode side current collector member 300 corresponds to a conductive member within the scope of claims.

As shown in FIGS. 4 to 6, the air electrode side current collector member 200 is arranged in the air chamber 166. As shown in the partially enlarged view of FIG. 5, the air electrode side current collector member 200 includes a metal member 210 and a conductive coating layer 220 formed on the surface of the metal member 210. The metal member 210 is formed of a metal containing Cr such as ferritic stainless steel. Further, the outermost surface side of the metal member 210 is composed of an oxide film layer 218 containing Cr oxide (for example, Cr ₂ O ₃ (chromia)).

Further, the coating layer 220 may be, for example, a spinel-type oxide (for example, Mn _1.5 Co _1.5 O ₄ , MnCo ₂ O ₄ , ZnCo ₂ O ₄ , ZnMn ₂ O ₄ , ZnMnCoO ₄ , CuMn ₂ O ₄ or the like. ) And perovskite-type oxides (for example, composite oxides containing La and Sr). The coating layer 220 is formed on the surface of the metal member 210 with a substantially uniform thickness (for example, 1 μm to 50 μm, preferably 5 μm to 30 μm). The coating layer 220 suppresses the diffusion of Cr from the metal member 210. As a result, for example, the generation of Cr poisoning of the air electrode 114 is suppressed.

The air electrode side current collector 200 is in contact with the surface of the air electrode 114 on the side opposite to the side facing the electrolyte layer 112 and the surface of the interconnector 150 on the side facing the air electrode 114. However, as described above, since the power generation unit 102 located at the top of the fuel cell stack 100 does not have the upper interconnector 150, the air electrode side current collecting member 200 in the power generation unit 102 is the interconnector 150. Instead, it is in contact with the upper end plate 104. The air electrode side current collector member 200 has such a configuration, and electrically connects the air electrode 114 and the interconnector 150 (or the end plate 104). The configuration of the air electrode side current collector 200 will be described in detail later. The air electrode side current collecting member 200 corresponds to a conductive member within the scope of claims.

A-2. Operation of fuel cell stack 100:
As shown in FIGS. 2 and 4, the oxidant gas OG is supplied via a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the oxidant gas introduction manifold 161. Then, the oxidant gas OG is supplied to the oxidant gas introduction manifold 161 through the holes of the branch portion 29 and the main body portion 28 of the gas passage member 27, and the oxidant gas introduction manifold 161 oxidizes each power generation unit 102. It is supplied to the air chamber 166 via the agent gas supply communication hole 132. Further, as shown in FIGS. 3 and 5, the fuel gas FG is supplied via a gas pipe (not shown) connected to the branch portion 29 of the gas passage member 27 provided at the position of the fuel gas introduction manifold 171. Then, the fuel gas FG is supplied to the fuel gas introduction manifold 171 through the holes of the branch portion 29 and the main body portion 28 of the gas passage member 27, and the fuel gas supply communication of each power generation unit 102 is performed from the fuel gas introduction manifold 171. It is supplied to the fuel chamber 176 through the hole 142.

When the oxidant gas OG is supplied to the air chamber 166 of each power generation unit 102 and the fuel gas FG is supplied to the fuel chamber 176, power is generated by the electrochemical reaction of the oxidant gas OG and the fuel gas FG in the single cell 110. Will be. This power generation reaction is an exothermic reaction. In each power generation unit 102, the air pole 114 of the single cell 110 is electrically connected to the upper interconnector 150 via the air pole side current collector member 200, and the fuel pole 116 is connected to the upper interconnector 150 via the fuel pole side current collector member 300. It is electrically connected to the lower interconnector 150. That is, the plurality of power generation units 102 included in the fuel cell stack 100 are electrically connected in series. Therefore, the electric energy generated in each power generation unit 102 is taken out from the end plates 104 and 106 that function as the output terminals of the fuel cell stack 100. Since the SOFC generates electricity at a relatively high temperature (for example, 700 ° C. to 1000 ° C.), the fuel cell stack 100 is a heater (for example, until the high temperature can be maintained by the heat generated by the power generation after the start-up. It may be heated by (not shown).

As shown in FIGS. 2 and 4, the oxidant off-gas OOG discharged from the air chamber 166 of each power generation unit 102 is discharged to the oxidant gas discharge manifold 162 through the oxidant gas discharge communication hole 133, and further oxidized. The fuel cell stack 100 is passed through the holes of the main body 28 and the branch 29 of the gas passage member 27 provided at the position of the agent gas discharge manifold 162, and the gas pipe (not shown) connected to the branch 29. It is discharged to the outside of. Further, as shown in FIGS. 3 and 5, the fuel off-gas FOG discharged from the fuel chamber 176 of each power generation unit 102 is discharged to the fuel gas discharge manifold 172 through the fuel gas discharge communication hole 143, and further, the fuel gas. To the outside of the fuel cell stack 100 via a gas pipe (not shown) connected to the branch portion 29 through the holes of the main body portion 28 and the branch portion 29 of the gas passage member 27 provided at the position of the discharge manifold 172. It is discharged.

A-3. Detailed description of the air electrode side current collector 200:
A-3-1. Manufacturing method of current collector member 200 on the air electrode side:
In explaining the air electrode side current collector member 200 in detail, for the sake of easy understanding, first, a method of manufacturing the air electrode side current collector member 200 will be described. FIG. 8 is a flowchart showing an example of a method of manufacturing the air electrode side current collector member 200. 9 to 11 are explanatory views showing an example of a method for manufacturing the air electrode side current collector member 200.

First, a metal member 210 is prepared, and a plurality of slits SL are formed in the metal member 210 (S110, see FIG. 9). The metal member 210 referred to here is a metal member 210 before processing, and by performing the processing described below, it becomes a metal member 210 (see FIG. 5) constituting the above-mentioned air electrode side current collector member 200. It is a thing. The metal member 210 is a substantially flat plate-shaped member made of a metal containing Cr (for example, ferritic stainless steel), and its thickness is, for example, 0.05 mm to 1 mm, preferably 0.1 mm to 0.5 mm. .. The metal member 210 corresponds to a metal plate within the scope of the claims.

Further, the shape of each slit SL formed in the metal member 210 in a plan view (Z-axis direction view) is, for example, a substantially U-shape (that is, a predetermined shape along three of the four sides constituting the rectangle). It is a shape having the width of). The slit SL may be a defective portion formed by cutting a predetermined portion of the metal member 210 by punching or the like, or may be a notch formed by a blade-shaped tool. That is, in the present specification, the term "slit (or" hole ")" is a concept including a notch. The width Ws of the slit SL is, for example, 2 μm to 3 mm, preferably 0.5 mm to 2 mm. The width Ws of the slit SL may be substantially constant throughout the slit SL, or may be different from each other at each position in the slit SL.

Further, in the present embodiment, a plurality of slits SL having the same orientation as each other are spaced apart from each other in the metal member 210 along a direction in which two of the three sides face each other (X-axis direction in FIG. 9). Slit group SLGs arranged so as to be arranged side by side and composed of a plurality of the arranged slits SL are spaced apart from each other along a direction perpendicular to the direction in which the two sides face each other (Y-axis direction in FIG. 9). Arranged so that they are lined up in a row. That is, the plurality of slits SL are arranged in a substantially grid pattern on the metal member 210.

Next, using a jig having a linear edge portion, the specific portion SP facing each of the plurality of slits SL in the metal member 210 is bent at a predetermined position in a direction perpendicular to a predetermined direction (. S120, see FIG. 10). The predetermined direction at the predetermined position at the time of this bending is a direction parallel to the first virtual straight line VL1 at the position of the first virtual straight line VL1 shown in FIGS. 9 and 10 (X-axis direction). .. That is, the specific portion SP is bent at the position of the first virtual straight line VL1 in the direction perpendicular to the first virtual straight line VL1 (Y-axis direction). As described above, the specific portion SP facing the slit SL in the metal member 210 is not limited to the portion facing the entire slit SL, and may be a portion facing a part of the slit SL. The shape of the specific portion SP in the plan view (Z-axis direction view) in the state before bending is, for example, a rectangle.

As shown in FIG. 9, in the first virtual straight line VL1, the slit SL formed in the metal member 210 in the state before bending of the specific portion SP is combined with the first slit portion SLP1 in the Z-axis direction. , A straight line that is virtually divided into a second slit portion SLP2 and a third slit portion SLP3. Here, the first slit portion SLP1 is a portion excluding both ends in the extending direction of the slit SL, and the second slit portion SLP2 and the third slit portion SLP3 are portions corresponding to both ends. That is, the second slit portion SLP2 is located on the side opposite to the first slit portion SLP1 (Y-axis positive direction side) with respect to the first virtual straight line VL1, and the predetermined position at the predetermined position. It is a portion continuous with the first slit portion SLP1 on one side (X-axis negative direction side) in the direction (direction parallel to the first virtual straight line VL1 at the position of the first virtual straight line VL1). Further, the third slit portion SLP3 is located on the side opposite to the first slit portion SLP1 (on the Y-axis positive direction side) with respect to the first virtual straight line VL1, and the above-mentioned predetermined position at the above-mentioned predetermined position. It is a portion continuous with the first slit portion SLP1 on the other side (the X-axis positive direction side in FIG. 9) in the direction (direction parallel to the first virtual straight line VL1 at the position of the first virtual straight line VL1). As described above, in the present embodiment, the first virtual straight line VL1 that defines the predetermined direction at the predetermined position when the specific portion SP is bent is the comparative virtual straight line VL0 (slit) as shown in FIG. The slit SL is set as a straight line that virtually divides the slit SL into the above three parts (SLP1, SLP2, SLP3), instead of a straight line that does not virtually divide the SL into a plurality of parts.

In the present embodiment, each specific portion SP is simultaneously (1) in a state where the linear edge portion of the jig is applied to the position of the first virtual straight line VL1 in each slit SL constituting the slit group SLG described above. Bent up (in the process). Such bending and raising of the specific portion SP in the slit group SLG unit is executed in order. It should be noted that the bending and raising of the specific portion SP does not necessarily have to be executed in units of the slit group SLG, and may be executed in order in each specific portion SP unit, or the specific portions arranged so as to be arranged in the same row. The SP may be executed at once (in one step), or all specific partial SPs may be executed at once (in one step). Further, the bending angle of the specific portion SP (that is, the angle formed by the surface of the first metal portion 211 (the surface substantially orthogonal to the Z axis) and the surface of the second metal portion 212 (described later)) θ1 is determined. For example, it is 5 degrees or more and 90 degrees or less, preferably 5 degrees or more and 20 degrees or less.

When the bending up (S120) of the specific portion SP is completed, as shown in FIG. 10, the metal member 210 has a substantially flat plate-shaped first metal portion 211 composed of a portion other than the specific portion SP, and the metal member 210. It is configured to have a second metal portion 212 composed of a substantially flat plate-shaped specific portion SP bent in the above. In this state, in the substantially flat plate-shaped first metal portion 211, a plurality of through holes corresponding to the region occupied by the slit SL and the specific portion SP in the state before bending of the specific portion SP (hereinafter, “metal member penetration”). A HOm (referred to as a "hole") is formed.

Next, using a jig having a linear edge portion, the tip portion EP at each of the plurality of second metal portions 212 of the metal member 210 is bent at a predetermined position in a direction perpendicular to a predetermined direction. (See S130, FIG. 11). The predetermined direction at the predetermined position at the time of this bending is a direction (X-axis direction) parallel to the second virtual straight line VL2 at the position of the second virtual straight line VL2 shown in FIGS. 10 and 11. That is, the tip portion EP is bent in the direction perpendicular to the second virtual straight line VL2 (Y-axis direction) at the position of the second virtual straight line VL2. The shape of the tip portion EP in the state after bending in a plan view (Z-axis direction view) is, for example, a rectangle. Further, the bending direction of the tip portion EP (rotation direction centered on the second virtual straight line VL2) is opposite to the bending direction of the specific portion SP described above (rotation direction centered on the first virtual straight line VL1). Is. The bending angle of the tip portion EP (that is, the angle formed by the surface of the third metal portion 213 and the surface of the fourth metal portion 214, which will be described later) θ2 is, for example, 5 degrees or more, preferably 90 degrees. The degree or less, more preferably 30 degrees or less.

In the present embodiment, the bending of the tip portion EP is sequentially performed in units of the plurality of second metal portions 212 corresponding to the slit group SLG described above, similar to the bending raising of the specific portion SP described above. It should be noted that the bending of the tip portion EP may be performed in units of individual tip portion EPs, or may be performed for the tip portion EPs arranged in the same row at one time (in one step). , May be performed at once (in one step) for all tip EPs.

When the bending (S130) of the tip portion EP is completed, as shown in FIG. 11, each second metal portion 212 is composed of the bent specific portion SP, and is a substantially flat plate-shaped fourth portion orthogonal to the Z-axis direction. The metal portion 214 of the above and the third metal portion 213 having a substantially flat plate shape, which is a portion other than the fourth metal portion 214 in the second metal portion 212, are configured. That is, the metal member 210 has a configuration including a first metal portion 211, a third metal portion 213, and a fourth metal portion 214 (that is, a second metal portion 212). After the above-mentioned processing on the metal member 210 before processing, the metal member 210 (see FIG. 5) constituting the above-mentioned air electrode side current collecting member 200 is manufactured.

Next, the coating layer 220 is formed on the metal member 210 (S140). The formation of the coating layer 220 is realized by applying the coating layer 220 by a well-known method such as spray coating, inkjet printing, spin coating, dip coating, plating, sputtering, thermal spraying, etc., and then performing heat treatment as necessary. .. By the above steps, the production of the air electrode side current collector member 200 is completed.

A-3-2. Detailed configuration of the air electrode side current collector 200:
12 and 13 are explanatory views showing a detailed configuration of the air electrode side current collector 200 in the present embodiment. FIG. 12 shows an enlarged XY cross-sectional structure of the X1 portion of FIG. Further, FIG. 13 shows the YZ cross-sectional configuration of the air electrode side current collector member 200 at the position of XIII-XIII in FIG. Hereinafter, the detailed configuration of the air electrode side current collector member 200 will be described mainly with reference to FIGS. 5, 12, and 13.

As shown in FIGS. 5, 12 and 13, the air electrode side current collector 200 includes a first conductive portion 231 and a second conductive portion 232. Further, the second conductive portion 232 has a third conductive portion 233 and a fourth conductive portion 234. The first conductive portion 231 is a portion composed of a first metal portion 211 (see FIG. 11 and the like) in the metal member 210 and a coating layer 220 covering the surface of the first metal portion 211. .. Further, the third conductive portion 233 is a portion composed of a third metal portion 213 (see FIG. 11 and the like) in the metal member 210 and a covering layer 220 covering the surface of the third metal portion 213. Is. Further, the fourth conductive portion 234 is a portion composed of a fourth metal portion 214 (see FIG. 11 and the like) in the metal member 210 and a coating layer 220 covering the surface of the fourth metal portion 214. Is.

In the present embodiment, the first conductive portion 231 of the air electrode side current collecting member 200 is in contact with the interconnector 150 (or the end plate 104), and each fourth conductive portion 234 is a single cell 110. Is in contact with the air electrode 114 of. Further, the third conductive portion 233 connects the first conductive portion 231 and each fourth conductive portion 234. Since the current collector member 200 on the air electrode side has such a configuration, as described above, the air electrode 114 of the single cell 110 and the interconnector 150 (or the end plate 104) are electrically connected.

As shown in the partially enlarged view of FIG. 5, between the first conductive portion 231 and the air pole 114 of the air electrode side current collector member 200, and between the fourth metal portion 214 and the interconnector 150 (or A spacer 139 formed of, for example, mica is arranged between the end plate 104). Due to the presence of these spacers 139, the air electrode side current collector 200 follows the deformation of the power generation unit 102 due to the temperature cycle and the reaction gas pressure fluctuation, and the air electrode 114 and the interconnector 150 via the air electrode side current collector 200 follow. Good electrical connection with (or end plate 104) is maintained.

The first conductive portion 231 of the air electrode side current collector member 200 has a substantially flat plate shape orthogonal to the Z-axis direction. Here, the substantially flat plate shape orthogonal to the Z-axis direction is not limited to a strict flat plate shape orthogonal to the Z-axis direction, and includes a portion having an inclination of less than 5 degrees with respect to a virtual plane orthogonal to the Z-axis direction. Including shape. For example, a virtual portion (Y1 portion in FIGS. 12 and 13) sandwiched between the second hole portion HP2 and the third hole portion HP3, which will be described later, in the first conductive portion 231 is orthogonal to the Z-axis direction. It may have an inclination of less than 5 degrees with respect to the plane, and the other portion of the first conductive portion 231 may be parallel to the virtual plane orthogonal to the Z-axis direction.

Further, a plurality of through holes HOc are formed in the first conductive portion 231 of the air electrode side current collector member 200. The through hole HOc formed in the first conductive portion 231 is a hole corresponding to the metal member through hole HOm (see FIG. 11) formed in the metal member 210. That is, it is formed at a position corresponding to the metal member through hole HOm in the air pole side current collector 200 manufactured by covering the surface of the metal member 210 on which the metal member through hole HOm is formed with the coating layer 220. The hole is a through hole HOc.

Further, the second conductive portion 232 of the air electrode side current collecting member 200 is the inner circumference of the first conductive portion 231 forming the through hole HOc in the Z-axis direction (more specifically, FIG. 12 and FIG. 12 and A plate-shaped portion (that is, a third conductive portion 233) extending in a direction intersecting the surface of the first conductive portion 231 (a surface substantially parallel to the Z axis) from the edge portion of the Y1 portion in FIG. Includes. The angle formed by the surface of the first conductive portion 231 and the surface of the third conductive portion 233 is the bending angle θ1 of the specific portion SP during the manufacture of the above-mentioned air electrode side current collector member 200 (FIG. 10). Further, the second conductive portion 232 further includes a substantially flat plate-shaped portion (fourth conductive portion 234) orthogonal to the Z-axis direction on the tip end side opposite to the boundary line BL. The angle formed by the surface of the third conductive portion 233 and the surface of the fourth conductive portion 234 is the bending angle θ2 of the tip portion EP during the manufacture of the above-mentioned air electrode side current collector 200 (FIG. 11). See).

As shown in FIG. 12, the through hole HOc formed in the first conductive portion 231 of the air electrode side current collector member 200 includes the first hole portion HP1, the second hole portion HP2, and the third hole portion HP2. It has a hole portion HP3. The first hole portion HP1 is a direction (Y-axis direction) orthogonal to the boundary line BL between the first conductive portion 231 and the second conductive portion 232 in the Z-axis direction, and is within the scope of claims. In (corresponding to the second direction), it faces the entire virtual line segment VS. Here, the virtual line segment VS has two intersections P1 of a straight line passing through the boundary line BL (that is, the first virtual straight line VL1) and an inner circumference forming the through hole HOc of the first conductive portion 231. , A virtual line segment connecting P2. The phrase "the first hole portion HP1 faces the entire virtual line segment VS" here refers only to the first conductive portion 231 (that is, the second conductive portion 232). The relationship between the first hole portion HP1 and the virtual line segment VS in the Z-axis direction is defined.

Further, the second hole portion HP2 is on the opposite side (Y axis) of the virtual line segment VS with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction) in the Z-axis direction. One side (X-axis negative direction) of the boundary line BL located on the positive direction side) and in the direction parallel to the virtual line segment VS (X-axis direction and corresponding to the third direction in the scope of the patent claim). On the side), it is continuous with the first hole portion HP1. Further, the third hole portion HP3 is on the opposite side (Y axis) of the virtual line segment VS with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction) in the Z-axis direction. It is located on the positive direction side) and is continuous with the first hole portion HP1 on the other side (X-axis positive direction side) of the boundary line BL in the direction parallel to the virtual line segment VS (X-axis direction). ..

Further, in the present embodiment, as shown in FIG. 12, the width of the first conductive portion 231 and the width of the second conductive portion 232 on the virtual line segment VS are equal to each other. That is, there is no step at the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232.

Further, FIG. 14 shows a posture in which the second conductive portion 232 of the air electrode side current collecting member 200 is substantially parallel to the first conductive portion 231 with reference to the boundary line BL (first virtual straight line VL1). The virtual state rotated in the direction of the arrow AR1 in FIG. 13 is shown so as to be. In this embodiment, since the inclination of the angle θ2 also exists between the third conductive portion 233 and the fourth conductive portion 234, the virtual state is based on the second virtual straight line VL2. The fourth conductive portion 234 is rotated in the direction of the arrow AR2 in FIG. 13 so as to be in a posture substantially parallel to the third conductive portion 233, and the first conductive portion 231 and the third conductive portion 233 are rotated. And the fourth conductive portion 234 are in a substantially parallel posture. That is, in the current collecting member 200 on the air electrode side in this virtual state, the covering layer 220 is formed on the metal member 210 (see FIG. 9) in the state before the bending of the specific portion SP (S120 in FIG. 8) is executed. Corresponds to the configuration. In this virtual state, the air electrode side current collector 200 satisfies the following equations (2) and (3). In this embodiment, the shapes of the second conductive portion 232 and the through hole HOc are symmetrical with respect to the perpendicular bisector of the boundary line BL.
ΔWb / 2 <Wbm / 2 ... (2)
Σtb <D ... (3)
however,
・ Wbm:
In the above virtual state, the metal member 210 (second) constituting the second conductive portion 232 at the second position separated by the distance L2 from the boundary line BL in the direction orthogonal to the boundary line BL (Y-axis direction). Width of metal portion 212) (hereinafter referred to as "width at the position of distance L2")
・ ΔWb:
In the virtual state, the width (width at the position of the distance L2) Wbm is subtracted from the opening width Wbo (where Wbo> Wbm) of the metal member 210 constituting the first hole portion HP1 at the second position. Difference (Wbo-Wbm)
・ D:
In the virtual state, on the outer periphery of the metal member 210 (second metal portion 212) constituting the second conductive portion 232 in the direction parallel to the virtual line segment VS (X-axis direction) at the second position. The shortest distance from the point to the inner circumference of the first conductive portion 231 forming the through hole HOc.
The sum of the thicknesses of the covering layers 220 at the positions at both ends of the shortest distance.

As shown in FIG. 14, in the above equation (2), “ΔWb / 2” is the edge of the first metal portion 211 in the Z-axis direction view (penetration of the metal member in the first metal portion 211) in the above virtual state. It represents the distance between the inner circumference forming the hole HOm) and the edge of the second metal portion 212 (outer circumference of the second metal portion 212). The fact that this "ΔWb / 2" is smaller than the width (width at the position of the distance L2) Wbm of the second metal portion 212 is half (Wbm / 2) of the second metal portion 212 at this position. It means that the width (width at the position of the distance L2) Wbm is relatively large. Further, as shown in FIG. 14, in the present embodiment, "D" in the above formula (3) is equal to "ΔWb / 2". The fact that this "D (= ΔWb / 2)" is larger than the total thickness of the coating layer 220, Σtb, is that the coating layer is on the surfaces of both the first metal portion 211 and the second metal portion 212 at this position. It means that 220 can be formed uniformly.

Further, since the air electrode side current collector 200 of the present embodiment is configured to satisfy the above equations (2) and (3) in the above virtual state, the following equation (1) is satisfied as a result. (See FIG. 12).
2 × ta <ΔWa / 2 <Wam / 2 ・ ・ ・ (1)
however,
・ Wam:
A first distance L1 along the surface of the second conductive portion 232 in a direction orthogonal to the boundary line BL from the boundary line BL (a direction inclined by an angle θ1 with respect to the XY plane (see FIG. 5)). The width of the metal member 210 (second metal portion 212) constituting the second conductive portion 232 at the position (hereinafter referred to as "width Wam at the position of the distance L1").
・ ΔWa:
The opening width of the metal member 210 (first metal portion 211) constituting the first conductive portion 231 at a position separated by the distance L1 from the boundary line BL in the direction orthogonal to the boundary line BL (Y-axis direction). Difference (Wao-Wam) obtained by subtracting the above width (width at the position of distance L1) Wam from Wao.
・ Ta:
Thickness of coating layer 220 at the first position

As shown in FIG. 12, in the above formula (1), “ΔWa / 2” forms the edge of the first metal portion 211 in the Z-axis direction (the metal member through hole HOm in the first metal portion 211). It represents the distance between the inner circumference) and the edge of the second metal portion 212 (the outer circumference of the second metal portion 212). The fact that this "ΔWa / 2" is larger than twice the thickness ta of the coating layer 220 (2 × ta) is that the coating layer is on the surface of the first metal portion 211 and the second metal portion 212 at this position. Even if the 220 is formed, it means that the members do not interfere with each other. Further, the fact that this "ΔWa / 2" is smaller than half the width (width at the position of the distance L1) Wam of the second metal portion 212 is the second metal portion at this position. It means that the width (width at the position of the distance L1) Wam of 212 is relatively large.

In this embodiment, since the air electrode side current collecting member 200 is manufactured by the above-mentioned manufacturing method, the length (size in the Y-axis direction) of the first hole portion HP1 with respect to the boundary line BL is set. , It is longer than the surface length (size in the Y-axis direction) of the second conductive portion 232 with respect to the boundary line BL.

A-3-3. Effect derived from the configuration of the air electrode side current collector 200 of this embodiment:
As described above, the air electrode side current collector 200 of the present embodiment includes a first conductive portion 231 including a metal (first metal portion 211) and a metal (second metal portion 212). It includes a second conductive portion 232. The first conductive portion 231 is a substantially flat plate-shaped portion orthogonal to the Z-axis direction. A through hole HOc is formed in the first conductive portion 231. Further, the second conductive portion 232 extends from the inner circumference of the first conductive portion 231 forming the through hole HOc in the Z-axis direction in a direction intersecting the surface of the first conductive portion 231. It includes a plate-shaped portion (third conductive portion 233). Further, the through hole HOc formed in the first conductive portion 231 has a first hole portion HP1, a second hole portion HP2, and a third hole portion HP3. The first hole portion HP1 passes through the boundary line BL in the direction orthogonal to the boundary line BL between the first conductive portion 231 and the second conductive portion 232 (Y-axis direction) in the Z-axis direction. It faces the entire virtual line segment VS connecting between the two intersections P1 and P2 of the straight line (first virtual straight line VL1) and the inner circumference of the first conductive portion 231. The second hole portion HP2 is located on the side opposite to the first hole portion HP1 (Y-axis positive direction side) with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction). Moreover, it is continuous with the first hole portion HP1 on one side (X-axis negative direction side) of the boundary line BL in the direction parallel to the virtual line segment VS (X-axis direction). Further, the third hole portion HP3 is located on the side opposite to the first hole portion HP1 (Y-axis positive direction side) with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction). In addition, it is continuous with the first hole portion HP1 on the other side (X-axis positive direction side) of the boundary line BL in the direction parallel to the virtual line segment VS (X-axis direction). Since the air pole side current collector 200 of the present embodiment has such a configuration, it is possible to suppress the occurrence of cracks in the air pole side current collector 200 due to stress concentration, as described below. ..

FIG. 15 is an explanatory diagram showing the configuration of the air electrode side current collector member 200X in the comparative example. The air pole side current collector 200X of the comparative example shown in FIG. 15 has a different shape of the first conductive portion 231 from the air pole side current collector 200 of the present embodiment shown in FIG. Specifically, in the air pole side current collector member 200X of the comparative example, the bending position of the metal member 210 during the bending process (S120 in FIG. 8) is not the position of the first virtual straight line VL1 but is compared. It is the position of the virtual straight line VL0 (see FIG. 9). Note that the comparative virtual straight line VL0 is a straight line that does not virtually divide the slit SL into a plurality of portions, unlike the first virtual straight line VL1. That is, in the air electrode side current collector member 200X of the comparative example, the through hole HOc is a straight line (comparative virtual straight line VL0) passing through the boundary line BL between the first conductive portion 231 and the second conductive portion 232. It is not divided into a plurality of parts by the virtual line segment VS connecting between the two intersections P1 and P2 with the inner circumference of the conductive part 231 of 1. As a result, in the air electrode side current collector member 200X of the comparative example, the second direction (Y-axis direction (however, the Y-axis direction (however, the first) orthogonal to the boundary line BL between the first conductive portion 231 and the second conductive portion 232). Of the parts facing the end of the through hole HOc in the (Y-axis positive direction, which is the direction opposite to the tip side of the conductive part 232 of 2)), the part constituting the bent part (hereinafter, “hole”). The end facing portion Y2 ”) coincides with the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232. Therefore, the hole end facing portion Y2 in the air electrode side current collector member 200X of the comparative example is bent at the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232. Since the air electrode side current collector 200X of the comparative example has such a configuration, it occurs when the air electrode side current collector 200X repeatedly expands and contracts, for example, during operation of the fuel cell stack 100. The stress is concentrated at a specific location (for example, the hole end facing portion Y2) of the air electrode side current collector member 200X. As a result, in the air electrode side current collector member 200X of the comparative example, cracks may occur at a specific position in the air electrode side current collector member 200X.

On the other hand, in the air electrode side current collector 200 of the present embodiment, as shown in FIG. 12, the through holes HOc formed in the first conductive portion 231 are the first conductive portion 231 and the second. By the virtual line segment VS connecting between the two intersections P1 and P2 of the straight line (first virtual straight line VL1) passing through the boundary line BL with the conductive portion 232 and the inner circumference of the first conductive portion 231. , The above-mentioned first hole portion HP1, second hole portion HP2, and third hole portion HP3. Therefore, in the air pole side current collecting member 200 of the present embodiment, the second portion orthogonal to the boundary line BL between the hole end facing portion Y2 (that is, the first conductive portion 231 and the second conductive portion 232). The first conductivity is the portion facing the end of the through hole HOc in the direction (however, the direction opposite to the tip end side of the second conductive portion 232), which constitutes the bent portion. It does not match the position of the boundary line BL between the sex portion 231 and the second conductive portion 232. Therefore, the hole end facing portion Y2 in the air electrode side current collector member 200 of the present embodiment is not bent like the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232. Instead, it has a substantially flat plate shape. Since the air electrode side current collecting member 200 of the present embodiment has such a configuration, for example, when the fuel cell stack 100 is operated, the air electrode side current collecting member 200 repeatedly expands and contracts. It is possible to prevent the generated stress from concentrating on a specific location (for example, the hole end facing portion Y2) of the air electrode side current collecting member 200. Therefore, according to the air electrode side current collecting member 200 of the present embodiment, it is possible to suppress the occurrence of cracks at a specific portion of the air electrode side current collecting member 200.

Further, in the air electrode side current collector 200 of the present embodiment, the width of the first conductive portion 231 and the width of the second conductive portion 232 on the virtual line segment VS are equal to each other. That is, there is no step at the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232. Therefore, according to the air electrode side current collector member 200 of the present embodiment, it is possible to effectively suppress the concentration of stress on a specific portion (for example, the hole end facing portion Y2) of the air electrode side current collector member 200. Therefore, it is possible to effectively suppress the occurrence of cracks at a specific portion of the air electrode side current collector member 200.

Further, in the air electrode side current collecting member 200 of the present embodiment, the first conductive portion 231 is a plate-shaped metal member 210 (first metal portion 211) containing Cr, and the first metal portion 211. It has a coating layer 220 formed on the surface of the metal portion 211 and suppressing the diffusion of Cr from the first metal portion 211. Similarly, the second conductive portion 232 is formed on the surface of the plate-shaped metal member 210 (second metal portion 212) containing Cr and the second metal portion 212, and the second metal portion 212 is formed. It has a coating layer 220 that suppresses the diffusion of Cr from the metal. That is, in the air electrode side current collector 200 of the present embodiment, the through hole HOc is divided into a first hole portion HP1, a second hole portion HP2, and a third hole portion HP3 by a virtual line segment VS. Therefore, in the current collecting member 200 on the air electrode side of the present embodiment, cracks are suppressed from occurring in the coating layer 220 at a specific portion of the metal member 210 (for example, a portion constituting the hole end facing portion Y2). be able to. Therefore, according to the air electrode side current collector member 200 of the present embodiment, the diffusion of Cr from the metal member 210 can be effectively suppressed by the coating layer 220.

Further, as described above, the air electrode side current collector 200 of the present embodiment satisfies the following formula (1).
2 × ta <ΔWa / 2 <Wam / 2 ・ ・ ・ (1)
Therefore, in the air electrode side current collector 200 of the present embodiment, the width (width at the position of the distance L1) Wam of the second metal portion 212 can be made relatively large, and the width of the second metal portion 212 and the first metal portion 211 can be relatively large. Even if the coating layer 220 is formed on the surface of the second metal portion 212, it is possible to suppress the occurrence of interference between the members (sites). Therefore, according to the air pole side current collecting member 200 of the present embodiment, the width (width at the position of the distance L1) Wam of the second metal portion 212 becomes smaller, and the air pole side current collecting member 200 collects the current. While avoiding a decrease in the electric function, it is possible to suppress the occurrence of peeling of the coating layer 220 and damage to the member due to interference between the members (sites).

Further, as described above, the air electrode side current collector 200 of the present embodiment satisfies the following equations (2) and (3).
ΔWb / 2 <Wbm / 2 ... (2)
Σtb <D ... (3)
Therefore, in the air electrode side current collecting member 200 of the present embodiment, when the metal member 210 including the first metal portion 211 and the second metal portion 212 is manufactured by bending (S120 in FIG. 8), the first The width (width at the position of the distance L2) Wbm of the metal portion 212 of 2 can be made relatively large, and the coating layer 220 is provided on the surfaces of both the first metal portion 211 and the second metal portion 212. It can be formed uniformly. Therefore, according to the air pole side current collector 200 of the present embodiment, the width (width at the position of the distance L2) Wbm of the second metal portion 212 becomes smaller, and the air pole side current collector 200 collects the current. The coating layer 220 can effectively suppress the diffusion of Cr from the metal member 210 while avoiding the deterioration of the electric function.

Further, in the air electrode side current collector 200 of the present embodiment, the coating layer 220 is configured to include at least one of a spinel type oxide and a perovskite type oxide. Therefore, according to the air electrode side current collector member 200 of the present embodiment, the diffusion of Cr from the metal member 210 can be effectively suppressed by the coating layer 220.

A-4. Detailed explanation of the fuel electrode side current collector member 300:
FIG. 16 is an explanatory diagram showing a detailed configuration of the fuel pole side current collector member 300 in the present embodiment. FIG. 16 shows an enlarged XY cross-sectional structure of the X2 portion of FIG. 7. Hereinafter, the detailed configuration of the fuel electrode side current collector member 300 will be described mainly with reference to FIGS. 4, 7, and 16. Since the configuration of the fuel electrode side current collector 300 is similar to the configuration of the air electrode side current collector 200 described above, the following is a description of the air electrode side current collector among the configurations of the fuel electrode side current collector 300. The points different from the configuration of the electric member 200 will be mainly described.

As shown in FIGS. 4, 7 and 16, the fuel pole side current collector member 300 includes a first conductive portion 301 and a second conductive portion 302. Further, the second conductive portion 302 has a third conductive portion 303 and a fourth conductive portion 304. In this embodiment, the fuel electrode side current collector member 300 is made of a conductive material such as nickel or nickel alloy. The fuel electrode side current collector member 300 is not covered with a coating layer like the air electrode side current collector member 200.

In the present embodiment, the first conductive portion 301 of the fuel electrode side current collector member 300 is in contact with the interconnector 150 (or the end plate 106), and each fourth conductive portion 304 is a single cell 110. Is in contact with the fuel electrode 116 of. Further, the third conductive portion 303 connects the first conductive portion 301 and each fourth conductive portion 304. Since the fuel pole side current collector member 300 has such a configuration, as described above, the fuel pole 116 of the single cell 110 and the interconnector 150 (or the end plate 106) are electrically connected.

A spacer 149 formed of, for example, a mica is arranged between the first conductive portion 301 and the fourth conductive portion 304 of the fuel electrode side current collector member 300. Due to the presence of the spacer 149, the fuel electrode side current collector member 300 follows the deformation of the power generation unit 102 due to the temperature cycle and the reaction gas pressure fluctuation, and interacts with the fuel electrode 116 of the single cell 110 via the fuel electrode side current collector member 300. Good electrical connection with connector 150 (or end plate 106) is maintained.

The first conductive portion 301 of the fuel electrode side current collector member 300 has a substantially flat plate shape orthogonal to the Z-axis direction. Here, the substantially flat plate shape orthogonal to the Z-axis direction is not limited to a strict flat plate shape orthogonal to the Z-axis direction, and includes a portion having an inclination of less than 5 degrees with respect to a virtual plane orthogonal to the Z-axis direction. Including shape. Further, a through hole HOa is formed in the first conductive portion 301 of the fuel electrode side current collector member 300.

Further, the second conductive portion 302 of the fuel electrode side current collector member 300 is the inner circumference of the first conductive portion 301 forming the through hole HOa in the Z-axis direction (more specifically, FIG. 16). A plate-like portion (that is, a third conductive portion 303) extending in a direction intersecting the surface (surface substantially parallel to the Z axis) of the first conductive portion 301 from the edge portion of the Y3 portion) is included. There is. In the present embodiment, the angle formed by the surface of the first conductive portion 301 and the surface of the third conductive portion 303 is approximately 90 degrees. Further, the second conductive portion 302 further includes a substantially flat plate-shaped portion (fourth conductive portion 304) orthogonal to the Z-axis direction on the tip end side opposite to the boundary line BL. In the present embodiment, the angle formed by the surface of the third conductive portion 303 and the surface of the fourth conductive portion 304 is approximately 90 degrees.

The through hole HOa formed in the first conductive portion 301 of the fuel electrode side current collector member 300 has a first hole portion HP1, a second hole portion HP2, and a third hole portion HP3. ing. The first hole portion HP1 is a direction (Y-axis direction) orthogonal to the boundary line BL between the first conductive portion 301 and the second conductive portion 302 in the Z-axis direction, and is within the scope of claims. In (corresponding to the second direction), it faces the entire virtual line segment VS. Here, the virtual line segment VS has two: a straight line passing through the boundary line BL (that is, the third virtual straight line VL3 in FIG. 16) and the inner circumference forming the through hole HOa of the first conductive portion 301. It is a virtual line segment connecting two intersections P3 and P4.

Further, the second hole portion HP2 is on the opposite side (Y axis) of the virtual line segment VS with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction) in the Z-axis direction. One side (X-axis negative direction) of the boundary line BL located on the negative direction side) and in the direction parallel to the virtual line segment VS (X-axis direction and corresponding to the third direction in the scope of the patent claim). On the side), it is continuous with the first hole portion HP1. Further, the third hole portion HP3 is on the opposite side (Y axis) of the virtual line segment VS with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction) in the Z-axis direction. It is located on the negative direction side) and is continuous with the first hole portion HP1 on the other side (X-axis positive direction side) of the boundary line BL in the direction parallel to the virtual line segment VS (X-axis direction). ..

Further, in the present embodiment, the width of the first conductive portion 301 and the width of the second conductive portion 302 on the virtual line segment VS are equal to each other. That is, there is no step at the position of the boundary line BL between the first conductive portion 301 and the second conductive portion 302.

The fuel pole side current collector member 300 having the above-described configuration can be manufactured by the same method as the above-mentioned manufacturing method of the air pole side current collector member 200 with reference to FIG. However, the direction and angle of the bending raising / bending process during the manufacture of the fuel pole side current collector member 300 are different from those during the manufacture of the air pole side current collector member 200. Further, since the fuel electrode side current collector member 300 does not have the coating layer 220, the step of forming the coating layer 220 executed when the air electrode side current collector member 200 is manufactured is the fuel electrode side current collector member 300. Not performed during the manufacture of.

As described above, the fuel pole side current collector member 300 of the present embodiment includes a first metal conductive portion 301 and a second metal conductive portion 302. The first conductive portion 301 is a substantially flat plate-shaped portion orthogonal to the Z-axis direction. A through hole HOa is formed in the first conductive portion 301. Further, the second conductive portion 302 extends from the inner circumference of the first conductive portion 301 forming the through hole HOa in the Z-axis direction in a direction intersecting the surface of the first conductive portion 301. It includes a plate-shaped portion (third conductive portion 303). Further, the through hole HOa formed in the first conductive portion 301 has a first hole portion HP1, a second hole portion HP2, and a third hole portion HP3. The first hole portion HP1 passes through the boundary line BL in the direction orthogonal to the boundary line BL between the first conductive portion 301 and the second conductive portion 302 (Y-axis direction) in the Z-axis direction. It faces the entire virtual line segment VS connecting between the two intersections P3 and P4 of the straight line (third virtual straight line VL3) and the inner circumference of the first conductive portion 301. The second hole portion HP2 is located on the side opposite to the first hole portion HP1 with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction), and is in the virtual line segment VS. It is continuous with the first hole portion HP1 on one side (X-axis negative direction side) of the boundary line BL in the parallel direction (X-axis direction). Further, the third hole portion HP3 is located on the side opposite to the first hole portion HP1 with respect to the virtual line segment VS in the direction orthogonal to the boundary line BL (Y-axis direction), and the virtual line segment It is continuous with the first hole portion HP1 on the other side (X-axis positive direction side) of the boundary line BL in the direction parallel to VS (X-axis direction). Therefore, according to the fuel electrode side current collector member 300 of the present embodiment, the specific location (for example, the first conductivity) of the fuel electrode side current collector member 300 is the same as described above for the air electrode side current collector member 200. The bent portion of the portion facing the end of the through hole HOa in the second direction (Y-axis direction) orthogonal to the boundary line BL between the sex portion 301 and the second conductive portion 302 constitutes. It is possible to suppress the concentration of stress at a location (the hole end facing portion Y4 shown in FIG. 16), and it is possible to suppress the occurrence of cracks at a specific location of the fuel electrode side current collector member 300. ..

Further, in the fuel pole side current collector member 300 of the present embodiment, the width of the first conductive portion 301 and the width of the second conductive portion 302 on the virtual line segment VS are equal to each other. That is, there is no step at the position of the boundary line BL between the first conductive portion 301 and the second conductive portion 302. Therefore, according to the fuel pole side current collector member 300 of the present embodiment, it is possible to effectively suppress the concentration of stress on a specific portion (for example, the hole end facing portion Y4) of the fuel pole side current collector member 300. Therefore, it is possible to effectively suppress the occurrence of cracks at a specific portion of the fuel electrode side current collector member 300.

B. Modification example:
The technique disclosed in the present specification is not limited to the above-described embodiment, and can be transformed into various forms without departing from the gist thereof, and for example, the following modifications are also possible.

The configuration of the single cell 110, the air pole side current collecting member 200, the fuel pole side current collecting member 300, the power generation unit 102, or the fuel cell stack 100 in the above embodiment is merely an example and can be variously modified. For example, in the air pole side current collector 200 of the above embodiment, the width of the first conductive portion 231 and the width of the second conductive portion 232 on the virtual line segment VS are equal to each other (FIG. 12). (See), assuming that the width of the first conductive portion 231 on the virtual line segment VS is larger than the width of the second conductive portion 232 as in the modified example of the air pole side current collector 200 shown in FIG. May be good. In the air pole side current collector 200 of the modified example shown in FIG. 17, the through hole HOc formed in the first conductive portion 231 is the first, as in the air pole side current collector 200 of the above embodiment. Between the two intersections P1 and P2 of the straight line (first virtual straight line VL1) passing through the boundary line BL between the conductive portion 231 and the second conductive portion 232 and the inner circumference of the first conductive portion 231. It is divided into a first hole portion HP1, a second hole portion HP2, and a third hole portion HP3 by a virtual line segment VS connecting the two. Therefore, in the modified example of the current collector 200 on the air electrode side shown in FIG. 17, the hole end facing portion Y2 (that is, orthogonal to the boundary line BL between the first conductive portion 231 and the second conductive portion 232). The portion facing the end of the through hole HOc in the second direction (however, the direction opposite to the tip end side of the second conductive portion 232) is the portion constituting the bent portion). It does not match the position of the boundary line BL between the conductive portion 231 of 1 and the conductive portion 232 of the second. That is, the hole end facing portion Y2 in the air pole side current collecting member 200 of the comparative example shown in FIG. 17 is like the position of the boundary line BL between the first conductive portion 231 and the second conductive portion 232. , Not continuous with the third conductive portion 233 stretched in a direction intersecting a surface substantially parallel to the first conductive portion 231 (eg, not bent) and to the first conductive portion 231. It has a substantially parallel flat plate shape. Therefore, even in the modified example of the air electrode side current collector 200 shown in FIG. 17, the stress generated by the air electrode side current collector 200 repeating thermal expansion and contraction during operation of the fuel cell stack 100, for example. However, it is possible to prevent the air electrode side current collecting member 200 from concentrating on a specific portion (for example, the hole end facing portion Y2). Therefore, even in the modified example of the air electrode side current collector 200 shown in FIG. 17, it is possible to suppress the occurrence of cracks at a specific portion of the air electrode side current collector 200.

Further, in the above embodiment, a virtual state in which the second conductive portion 232 of the air electrode side current collecting member 200 is rotated so as to be substantially parallel to the first conductive portion 231 with reference to the boundary line BL. In (see FIG. 14), the shape of the second conductive portion 232 in the Z-axis direction is substantially rectangular, but like the air electrode side current collecting member 200 of the modified example shown in FIGS. 18 and 19. In the virtual state (state shown in FIG. 19), the shape of the second conductive portion 232 in the Z-axis direction may be another shape (for example, a substantially trapezoidal shape).

In the modified air pole side current collector 200 shown in FIGS. 18 and 19, the following equation (2) and the following equation (2) and the following equation (2) and (3) is satisfied.
ΔWb / 2 <Wbm / 2 ... (2)
Σtb <D ... (3)

Further, in the modified air pole side current collector member 200 shown in FIGS. 18 and 19, the following is performed in a normal state (FIG. 18) which is not a virtual state, like the air pole side current collector member 200 of the above embodiment. Equation (1) is satisfied.
2 × ta <ΔWa / 2 <Wam / 2 ・ ・ ・ (1)

Further, in the above embodiment, the second conductive portion 232 of the air electrode side current collector member 200 extends in a direction intersecting the surface of the third conductive portion 233 (that is, the first conductive portion 231). It is composed of a plate-shaped portion) and a fourth conductive portion 234 (that is, a substantially flat plate-shaped portion orthogonal to the Z-axis direction), and the second conductive portion 232 is the fourth conductive portion. It may be composed of only the third conductive portion 233 without having the portion 234. In such a configuration, the third conductive portion 233 will be connected to the air electrode 114.

Similarly, in the above embodiment, the second conductive portion 302 of the fuel electrode side current collector member 300 extends in a direction intersecting the surface of the third conductive portion 303 (that is, the first conductive portion 301). A plate-shaped portion) and a fourth conductive portion 304 (that is, a substantially flat plate-shaped portion orthogonal to the Z-axis direction), wherein the second conductive portion 302 is a fourth conductive portion. It may be composed of only the third conductive portion 303 without having the sex portion 304. In such a configuration, the third conductive portion 303 will be connected to the fuel electrode 116.

Further, in the above embodiment, the first conductive portion 231 of the air electrode side current collector member 200 is in contact with the interconnector 150 (or the end plate 104), and the fourth conductive portion 232 constitutes the second conductive portion 232. The conductive portion 234 of the above is in contact with the air electrode 114, whereas the second conductive portion 232 is in contact with the interconnector 150 (or end plate 104) and the first conductive portion 231 is in contact with the air electrode 114. It may be in contact with the air electrode 114.

Similarly, in the above embodiment, the first conductive portion 301 of the fuel electrode side current collector member 300 is in contact with the interconnector 150 (or the end plate 106), and the second conductive portion 302 constitutes the second conductive portion 302. The conductive portion 304 of 4 is in contact with the fuel electrode 116, whereas the second conductive portion 302 is in contact with the interconnector 150 (or end plate 106), and conversely, the first conductive portion 301. May be in contact with the fuel electrode 116.

Further, in the above embodiment, the shape of the air pole side current collector member 200 may be the same as the shape of the fuel pole side current collector member 300. That is, the shape of the air electrode side current collector 200 in the above embodiment is the bending direction (rotational direction) of the third conductive portion 233 with respect to the first conductive portion 231 and the third conductive portion. The shape is such that the bending direction (rotation direction) of the fourth conductive portion 234 with respect to 233 is opposite, but the bending directions of both are the same as in the fuel electrode side current collector member 300. It may be a shape.

Similarly, in the above embodiment, the shape of the fuel pole side current collector member 300 may be the same as the shape of the air pole side current collector member 200. That is, the shape of the fuel pole side current collector member 300 in the above embodiment is the bending direction (rotational direction) of the third conductive portion 303 with respect to the first conductive portion 301 and the third conductive portion. The shape is such that the bending direction (rotation direction) of the fourth conductive portion 304 with respect to 303 is the same direction, but the bending directions of both are opposite to each other, as in the case of the air electrode side current collector member 200. It may be a shape.

Further, in the above embodiment, the air electrode side current collector 200 is composed of the metal member 210 and the coating layer 220, but the air electrode side current collector 200 does not have the coating layer 220 and is a metal member. It may be composed of only 210. Further, in the above embodiment, the fuel electrode side current collecting member 300 does not have a coating layer, but the fuel electrode side current collecting member 300 is a metal member formed of a metal containing Cr (for example, ferritic stainless steel). And may be composed of a coating layer formed of a conductive material (for example, Ni or the like) and covering the metal member.

Further, in the above embodiment, the air electrode side current collecting member 200 is in contact with the air electrode 114 without passing through the bonding layer, but the air electrode side current collecting member 200 is in contact with the air electrode 114 via the bonding layer. May be. Further, in the above embodiment, the fuel electrode side current collector member 300 is in contact with the fuel electrode 116 without passing through the junction layer, but even if the fuel electrode side current collector member 300 is in contact with the fuel electrode 116 via the junction layer. good.

Further, in the above embodiment, between the first conductive portion 231 and the air pole 114 of the air electrode side current collector member 200, and between the fourth metal portion 214 and the interconnector 150 (or the end plate 104). Spacers 139 are arranged between them, but one or both of these spacers 139 may not be arranged.

Further, in the above embodiment, among the corner portions forming the second hole portion HP2, the corner portion closest to the third hole portion HP3 in the X-axis direction (third direction) and the third hole portion HP3. Of the corner portions forming the above, at least one of the corner portions closest to the second hole portion HP2 in the X-axis direction (third direction) may be R-shaped. As shown in FIG. 12 and the like, among the corners forming the second hole HP2, the corner closest to the third hole HP3 in the X-axis direction (third direction) and the third hole. Among the corners forming the partial HP3, the corner closest to the second hole portion HP2 in the X-axis direction (third direction) is the hole end facing portion Y2 in the air electrode side current collector member 200. Therefore, if at least one of these corners has an R shape, the concentration of stress can be suppressed extremely effectively, and the occurrence of cracks can be suppressed extremely effectively. The curvature of the R shape is preferably 0.1 mm to 1 mm or more, and preferably 0.25 mm to 0.75 mm or less.

Further, in the above embodiment, the number of power generation units 102 included in the fuel cell stack 100 is only an example, and the number of power generation units 102 is appropriately determined according to the output voltage and the like required for the fuel cell stack 100. Further, it is necessary that the configurations described in the above embodiments are adopted for both the air pole side current collecting member 200 and the fuel pole side current collecting member 300 in all of the plurality of power generation units 102 constituting the fuel cell stack 100. Instead, the configuration described in the above embodiment is adopted for at least one of the air pole side current collecting member 200 and the fuel pole side current collecting member 300 in at least one of the plurality of power generation units 102 constituting the fuel cell stack 100. You just have to.

Further, in the above embodiment, the fuel cell stack 100 is formed with manifolds 161, 162, 171 and 172 which are flow paths for supplying or discharging gas, and these manifolds 161, 162, 171 and 172 are formed. Such a flow path may not be formed for at least one of the fuel cells, and gas may be directly exchanged between the outside of the fuel cell stack 100 and the gas chamber (air chamber 166 or fuel chamber 176). ..

Further, the material constituting each member in the above embodiment is merely an example, and each member may be composed of another material. For example, in the above embodiment, the metal member 210 constituting the air electrode side current collector member 200 is made of ferritic stainless steel, but the metal member 210 may be made of another material. Further, in the above embodiment, the coating layer 220 constituting the air electrode side current collecting member 200 is configured to contain at least one of a spinel type oxide and a perovskite type oxide, but the coating layer 220 is a spinel type. It may be formed of materials other than oxides and perovskite-type oxides.

Further, the method of manufacturing the fuel electrode side current collector member 300 and the air electrode side current collector member 200 in the above embodiment is merely an example and can be variously modified. For example, when manufacturing the fuel electrode side current collector member 300 and / or the air electrode side current collector member 200, cutting, casting, joining, etching, or the like may be performed instead of the above-mentioned bending process.

Further, in the above embodiment, the fuel cell stack 100 has a configuration in which a plurality of substantially flat plate-shaped power generation units 102 (single cell 110) are arranged side by side, but the present invention has a power generation of another shape (for example, a cylindrical shape). The same applies to a fuel cell stack in which a plurality of units (single cells) are arranged side by side.

Further, in the above embodiment, the SOFC that generates power by utilizing the electrochemical reaction between hydrogen contained in the fuel gas and oxygen contained in the oxidizing agent gas is targeted, but the present invention relates to an electrolysis reaction of water. It is also applicable to an electrolytic cell unit, which is a constituent unit of a solid oxide type electrolytic cell (SOEC) that uses it to generate hydrogen, and an electrolytic cell stack having a plurality of electrolytic cell units. The configuration of the electrolytic cell stack is not described in detail here because it is known, for example, as described in Japanese Patent Application Laid-Open No. 2016-81813, but is schematically the same as the fuel cell stack 100 in the above-described embodiment. It is the composition of. That is, the fuel cell stack 100 in the above-described embodiment may be read as an electrolytic cell stack, the power generation unit 102 may be read as an electrolytic cell unit, and the single cell 110 may be read as an electrolytic cell. However, during the operation of the electrolytic cell stack, a voltage is applied between both electrodes so that the air electrode 114 is positive (anode) and the fuel electrode 116 is negative (cathode), and the voltage is applied through the communication hole 108. Steam as a raw material gas is supplied. As a result, an electrolysis reaction of water occurs in each electrolytic cell unit, hydrogen gas is generated in the fuel chamber 176, and hydrogen is taken out to the outside of the electrolytic cell stack through the communication hole 108. Even in the electrolytic cell unit and the electrolytic cell stack having such a configuration, by adopting the air electrode side current collector member 200 and the fuel electrode side current collector member 300 having the above-described configuration, the air electrode side current collector member 200 and the fuel electrode can be used. It is possible to suppress the occurrence of cracks at a specific location of the side current collector member 300.

Further, in the above embodiment, the solid oxide fuel cell (SOFC) has been described as an example, but the present invention can also be applied to other types of fuel cells (or electrolytic cells) such as a molten carbonate fuel cell (MCFC). Applicable. Further, the present invention is not limited to the current collecting member constituting the electrochemical reaction unit, but is a substantially flat plate shape containing a metal and orthogonal to the first direction, and the first conductive portion having a through hole formed therein. Includes a plate-like portion that contains metal and extends in a direction intersecting the surface of the first conductive portion from the inner circumference of the first conductive portion that forms the through hole in the first directional view. It is generally applicable to a conductive member comprising a second conductive portion.

22: Bolt 24: Nut 26: Insulation sheet 27: Gas passage member 28: Main body 29: Branch 100: Fuel cell stack 102: Fuel cell power generation unit 104: End plate 106: End plate 108: Communication hole 110: Single cell 112: Electrolyte layer 114: Air electrode 116: Fuel electrode 120: Separator 121: Hole 124: Joint 130: Air electrode side frame 131: Hole 132: Oxidizing agent gas supply communication hole 133: Oxidizing agent gas discharge communication hole 139: Spacer 140: Fuel pole side frame 141: Hole 142: Fuel gas supply communication hole 143: Fuel gas discharge communication hole 149: Spacer 150: Interconnector 152: Coating layer 161: Oxidating agent gas introduction manifold 162: Oxidating agent gas discharge manifold 166: Air chamber 171: Fuel gas introduction manifold 172: Fuel gas discharge manifold 176: Fuel chamber 200: Air electrode side current collector 210: Metal member 211: First metal part 212: Second metal part 213: Third metal Part 214: Fourth metal part 218: Oxide coating layer 220: Coating layer 231: First conductive part 232: Second conductive part 233: Third conductive part 234: Fourth conductive part 300 : Fuel pole side current collector 301: First conductive part 302: Second conductive part 303: Third conductive part 304: Fourth conductive part

Claims (11)

The first conductive portion containing a metal and having a substantially flat plate shape orthogonal to the first direction and having a through hole formed therein, and the first conductive portion containing a metal and forming the through hole in the first directional view. A conductive member comprising a second conductive portion including a first plate-shaped portion that is bent and extended in a direction intersecting the surface of the first conductive portion from the inner circumference of the conductive portion of 1. In
The second conductive portion is a substantially flat plate-shaped second plate-shaped portion orthogonal to the first direction, and the first conductivity is formed from the inner circumference of the first conductive portion. From the tip of the first plate-shaped portion that is bent and stretched in a direction intersecting the surface of the sex portion, the first conductive portion and the second conductive portion can be seen in the first direction. A second plate-shaped portion that is bent and stretched in a direction from the first conductive portion side toward the through hole side with respect to the boundary line is included.
The through hole is
In the first directional view,
Two, a straight line passing through the boundary line and an inner circumference of the first conductive part in a second direction orthogonal to the boundary line between the first conductive portion and the second conductive portion. The first hole facing the entire virtual line segment connecting the intersections,
In the second direction, on one side of the boundary line in the third direction parallel to the virtual line segment and located on the side opposite to the first hole portion with respect to the virtual line segment. A second hole portion continuous with the first hole portion and
In the second direction, the first hole portion is located on the side opposite to the first hole portion with respect to the virtual line segment, and on the other side of the boundary line in the third direction. With a third hole that is continuous with
A conductive member comprising. In the conductive member according to claim 1,
A conductive member, characterized in that the width of the first conductive portion and the width of the second conductive portion on the virtual line segment are equal to each other. In the conductive member according to claim 1 or 2.
Each of the first conductive portion and the second conductive portion is
A plate-shaped metal member containing Cr and
A coating layer formed on the surface of the metal member and suppressing the diffusion of Cr from the metal member,
A conductive member comprising. In the conductive member according to claim 3,
A conductive member, characterized in that it satisfies the following formula (1).
2 × ta <ΔWa / 2 <Wam / 2 ・ ・ ・ (1)
however,
Wam: The width ΔWa of the metal member at the first position separated by a distance L1 along the surface of the second conductive portion in the direction orthogonal to the boundary line from the boundary line: the second from the boundary line. The difference (Wao-Wam) obtained by subtracting the width Wam from the opening width Wao of the metal member at a position separated by the distance L1 in the direction of.
ta: Thickness of the coating layer at the first position In the conductive member according to claim 3,
A conductive member, characterized in that it satisfies the following formulas (2) and (3).
ΔWb / 2 <Wbm / 2 ... (2)
Σtb <D ... (3)
however,
Wbm: In a virtual state in which the second conductive portion is rotated so as to have a posture substantially parallel to the first conductive portion with reference to the boundary line, the second direction from the boundary line. Width ΔWb of the metal member constituting the second conductive portion at a second position separated by a distance L2: The metal constituting the first hole portion at the second position in the virtual state. Difference (Wbo-Wbm) obtained by subtracting the width Wbm from the opening width Wbo of the member.
D: In the virtual state, the shortest distance from a point on the outer circumference of the metal member constituting the second conductive portion in the third direction to the inner circumference in the second position Σtb: the shortest distance. The sum of the thicknesses of the coating layers at the positions at both ends of The conductive member according to any one of claims 3 to 5.
The coating layer is a conductive member containing at least one of a spinel-type oxide and a perovskite-type oxide. The conductive member according to any one of claims 1 to 6.
Among the corners forming the second hole portion, the corner portion closest to the third hole portion in the third direction and the corner portion forming the third hole portion, the third hole portion. A conductive member, characterized in that at least one of the corner portion closest to the second hole portion in the direction of is R-shaped. The conductive member according to any one of claims 1 to 7.
The conductive member is a conductive member for a solid oxide type electrochemical reaction unit. It is an electrochemical reaction unit,
An electrochemical reaction single cell containing an electrolyte layer containing a solid oxide and an air electrode and a fuel electrode facing each other in the first direction across the electrolyte layer.
The 1st to 8th claims, which are arranged on one side of the first direction with respect to the electrochemical reaction single cell and function as a current collecting member electrically connected to the air electrode or the fuel electrode. The conductive member according to any one of the items and
An electrochemical reaction unit characterized by comprising. In the electrochemical reaction unit according to claim 9,
The electrochemical reaction unit is an electrochemical reaction unit characterized by being a fuel cell power generation unit. In the electrochemical reaction cell stack having a plurality of electrochemical reaction units arranged side by side in the first direction.
The electrochemical reaction cell stack, wherein at least one of the plurality of electrochemical reaction units is the electrochemical reaction unit according to claim 9 or 10.

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